Expansible link strap



Sept., l 51953 E. KIEFER mgm EXPANSIBLE LINK STRAP Filed 1pm 1o, 1951 2 shee--sheez 1 @ayt l5, 1953 E. KIEFER Zm@ EXPANSIBLE LINK STRAP Filed April lo, 1951 2 Sheets-Sheet 2 IN VEN TOR.

Patented Sept. 15, 1953 OFFICE EXPANSIBLE LINK STRAP Emil Kiefer, Pforzheim, Germany, assignor to Richard A. Kiefer, Elberon, N. J.

Application April 10, 1951, Serial No. 220,255 In Germany October 4, 1948 8 Claims. 1

My present invention relates to expandable link-straps adapted to be used as wrist bands attached to watches, for example.

This case is a continuation-in-part of my U. S. application Number 57,073, which was led October 28, 1948, and which has matured into U. S. Patent Number 2,561,381, dated July 24, 1951.

My present invention is essentially an improvement over the expandable link-strap disclosed in the above-mentioned application. Due to the width of the spring supporting member in the expandable link-strap disclosed in the above mentioned application, the said link-strap is not expandable beyond a certain point, and if it were expandable beyond this point the adjoining ends of the strips of metal which form the flat sleeve members for the 1ink-strap would be visible.

Accordingly, one of the objects of my present invention is to provide an expandable link-strap which may be stretched to almost the entire limit permitted by the links thereof, the said stretching not being in any way prevented by any other elements of the expandable link-strap.

Another object of my present invention is to provide an expandable link-strap which will disclose only smooth continuous surfaces when it is completely stretched.

With the above objects in view my present invention mainly consists of an expandable linkstrap comprising, in combination, a plurality of frame members located adjacent to each other; a plurality of flat sleeve members each of which is located between a pair of said frame members, said flat sleeve members each being formed from a flat strip of material having its ends joined and located at an end of said flat sleeve members, so that said joined ends will not be visible in the space between said frame members when the latter are separated from each other during the stretching of the link-strap; means for slidably and pivotally connecting said frame and sleeve members to each other; spring support means located within said sleeve members and mounted at an end of said frame members, said spring support means being located in its entirety in the region of said end of said frame members; and spring means located within each of said at sleeve members, said spring means bearing at one end thereof against said support members and bearing at the other end thereof against an inner end of said sleeve members, said spring means extending over almost the entire length of said frame members when the strap is in its unstretched position, and said spring means being compressible over substantially its entire length because said support member is located in its entirety in the region of said end of said frame members, whereby said flat sleeve members are slidable over almost the entire length of said frame members so as to permit a maximum amount of stretching of said link--strap- The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description "f of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a view of one side of a blank strip from which a fiat sleeve member may be formed, the said dat sleeve member being one of the links in the expandable link-strap of my present invention;

Fig. 2 is an edge view of the strip shown in Fig. 1 after it has been bent so as to form the above mentioned flat sleeve member;

Fig. 3 is an elevational view of the flat sleeve member shown in Fig. 2, as it appears when looking down on the top side thereof;

Fig. 4 is a sectional view taken along line 4-4 of Fig. 2, looking in the direction of the arrows;

Fig. 5 is a sectional view taken along line 5-5 of Fig. 2, looking in the direction of the arrows;

Fig. 6 is an elevational side view of a spring support member constructed in accordance with my present invention;

Fig. 7 is an elevational view of a spring used in the expandable link-strap of my present invention;

Fig. 8 is an isometric view of a frame member which forms one of the links in the expandable link-strap of my present invention;

Fig. 9 is a sectional elevational view of the assembled parts of the expandable link-strap of my present invention; and

Fig. 10 is a sectional view taken along the line l0l0 of Fig. 9, looking in the direction of the arrows.

The expandable link-strap of my present invention is adapted to be made of a plurality of links of two types, one of which consists of the frame member shown in Fig. 8 and the other of which consists of flat sleeve members shown in Figs. 1 5.

The flat sleeve member shown in Figs. l-5 is made from a one-piece strip of material, preferably though not necessarily metal, which may be bent so as to form the nat sleeve member. As is shown in Fig. 1, the iiat strip I5 has projections I6 located at the left hand end thereof, and the projections I'I located at the right hand end thereof. Projections I8 are located substantially centrally of the projections IS and I'I. These projections are formed of the same material which forms strip I5 and are integral therewith in a preferred embodiment of the invention. Projections I6 are partially severed from the strip I5 along the lines I9 which coincide with the side edges of the strip I5. Projections I5 are also partially severed along the lines 2I in a similar manner. The right hand end of the strip shown in Fig. l is cut away at 22 so as to form a recess extending inwardly from the right hand end of the strip.

This strip is formed into a flat sleeve member by bending it around a line joining the projections I8, as is evident from the flat sleeve member shown in Fig. 2. Itwill be noted that in this way there are formed two opposite side portions 23 which are substantially parallel to each other and are spaced from each other. The severed parts of projections I8 are curled inwardly upon themselves, as shown in Fig. 2, so as to provide projections which facilitate the connection between the flat sleeve members and the frame members, as will be more fully explained below.

The right hand end of the strip shown in Fig. l is bent inwardly towards the lower side 23, as viewed in Fig. 2. The left hand end of the strip shown in Fig. 1 is bent upwardly toward the upper side 23, as viewed in Fig. 2, and the severed part of projections I6 are curled inwardly upon themselves and around the projection I?, as is clear from Fig. 2. Thus a rigid connection for the ends of strip I5 is provided which does not require Welding or other connection means.

The left hand end of the strip shown in Fig. l

The edge 24 of the strip I5 is located adjacent to the left hand end of the flat sleeve member, as viewed in Fig. 2. As will be evident from the description given below this edge 24 will never be visible even when the link-strap is fully expanded.

Frame members 25 are adapted to cooperate with the at sleeve members described above so as to form the expandable link-strap of my present invention. The frame member 25 comprises a flat body portion 26 which has trough-like recesses 2 formed on opposite sides thereof and confronting each other. The body portion 25 forms a continuation of one of the sides of the recesses 2'I.

In order to make the link-strap of my present invention expandable and automatically contractible, there are provided spring members 28, shown in Fig. 7 of the drawings.

Spring support members 29 are provided in order to support one end of the springs 28. The members 29 are formed in the central portion thereof with spaced projections 30 for a purpose which will be described below. The end portions 3I of elements 29 facilitate the mounting, thereof in the frame members 25, It will be noted that elements 29 are quite elongated and that the maximum width thereof is substantially less than 1/3 of the length thereof.

The above described parts of the expandable link-strap of my present invention are assembled in the manner shown in Figs. 9 and l0. The spring 28 is located within the space between the sides 23 of the flat sleeve member and has one end thereof located in the recess formed by the cut away portion 22 and the left hand end portion of the strip I5, as viewed in Fig. 1. The spring support members 29 are also located respectively within the spaces between the sides 23 of the nat sleeve members `and the end portions 3I of spring support members 29 are located at the ends of a pair of the opposite trough-like recesses 21, as is clearly shown in Fig. 9. The projections I8 of the flat sleeve members are located at one end of the trough-like recesses 21 in the frame members 25, and the flat sleeve members extend therefrom into the adjacent frame members 25 with their projections I6 located in the opposite recesses 2l thereof.

The parts are shown in the unstretched position of the link-strap in Figs. 9 and 16. It will thus be seen that in this position of the parts the spring 28 extends over substantially the entire length of the frame member 25 and that the ends I8 cooperate with the ends of the recesses 2? so as to pivotally support the adjacent links with respect to each other. It will be noted also that the member 29 is of such a narrow width that it is located in its entirety in the region of the end of frame member 25. The projections 35 of the spring support 29 form a convenient base about which the right hand end coil of the spring 28 may be located, as viewed in Fig, 9, and the space between the projections 30 is adapted to accommodate the extremity of the spring 28 which may be bent so as to be located between projections 30 and thereby provide an eicient connection between the spring 2B and spring support 29.

When the link-strap of my present invention is expanded, the springs 28 may be compressed over almost their entire length, and the projections I6 can be moved along the troughs 21 until they are located `almost next to the right hand end of frame members 25, as viewed in Fig. 9. Only the projections 3| of the spring supports 29 prevent the projections I6 from contacting the extreme ends of the troughs 2l'. It will be noted that in the extreme. stretched position of the above-described link-strap the edge 24 is still locatedv within the frame member 25 so that only the continuous side surfaces 23 of the flat sleeve members are visible in the spaces formed between frame members 25 when the link-strap is stretched.

. It will be evident that the above-described linkstrap may be stretched to a length which is only slightly less than the sum of the lengths of the links formed by the frame members 25 and the nat sleeve members. Also the appearance of the link-strap in its extreme stretched position is not marred by any connection line between the ends of the strip I5, since edge 24 is always located within the frame member 25. The links of the `extendable strap o1" my present invention may be separated simply by tilting the flat sleeve members and spring supports 29 so that the projections IB and 3| are removed from the recesses 21, and then the fiat sleeve member may be removed from the adjacent frame member 25 by tilting it so that the projections I8 are removed from the recesses 21. The recess formed by cut away portion 22 and the left end of the strip l5, as viewed in Fig. l, forms a very efficient support for the end of the spring 28 distant from spring support 29. since this spring is made of such a size that its end coil accurately fits into this recess.

It will be understood that each of the elements described above, or two or more together, may also nd a useful application in other types of straps differing from the types described above.

While I have illustrated and described the invention as embodied in expandable link-straps, I do not intend to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of my invention.

Without further analysis, the foregoing will so fully reveal the gist of my invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specic aspects oi this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What I claim as new and desire to secure by Letters Patent is:

l. A blank for forming therefrom a ilat sleeve member for use in an expandable linkestrap consisting of a single strip of material having first and second ends and having three projecting portions located opposite to each other on opposite sides of said strip, two of the projections on each of said sides of the strip being located at the ends of the strip and the third projection on each of said sides of the strip being located substantially centrally of said projections at the ends of the strip, the projections at the rst end of the strip being of a substantially smaller width than the projections at the second end of the strip, and said last mentioned projections and said centrally located projections being partially severed from said strip along lines which form a continuation of the sides of said strip.

2. A blank for forming therefrom a flat sleeve member for use in an expandable link-strap consisting of a single strip of material having first and second ends and having three projecting portions located opposite to each other on opposite sides of said strip, two of the projections on each of said sides of the strip being located at the ends of the strip and the third projection on each of said sides of the strip being located substantially centrally of said projections at the ends of the strip, the projections at the first end of the strip being of a substantially smaller width than the projections at the second end of the strip, said last mentioned projections and said centrally located projections being partially severed from said strip along lines which form a continuation of the sides of said strip, said first end of said strip having a portion thereof cut away inwardly of the projections of smaller width.

3. A spring support member for an expandable ink-strap consisting of an elongated member having a maximum width which is less than 1/3 of the length of said elongated member, said elongated member having a pair of end portions adapted to be mounted in the expandable linkstrap and having a central portion adapted to support an end of a spring for said expandable link-strap, said central portion being formed with a pair of spaced projections extending laterally 6 from one side of said elongated member, said projections being adapted to support the end coil of a spring for said expandable link-strap and being set oir with respect to said end portions by a distance which is at least as great as the extent of projection of said pair of projections.

4. An expandable link-strap comprising, in combination, a plurality 0f frame members located adjacent to each other and each having a fiat body portion terminating in a pair of oppositely located trough like recesses, said recesses being substantially parallel to each other and confronting each other and said flat body-portion forming a continuation of one of the sides of said recesses so that said recesses are located in their entirety on one side of said flat body portion of said frame member; a plurality of flat sleeve members interconnecting adjacent pairs of said frame members which are located next to each other, said fiat sleeve members each having a pair of opposite side portions located in spaced and parallel relation to each other and connected at their ends by a pair of end portions formed integrally with said side portions and extending beyond the edges of said side portions so as to form projections, said projections being located in said trough like recesses of said frame members and said side portions of said sleeve members being located between said recesses, said sleeve members each extending from a point intermediate the ends of one frame member beyond the latter to a point intermediate the ends of the next frame member; a plurality of elongated spring support members each having a central portion of a maximum width which is substantially less than 1/3 of the length thereof and having ends located in said recesses of said frame members at one end thereof, said ends being offset with respect to said central portion by a distance at least as great as the width of said central portion so that said spring support members each extend from the end of one recess to the corresponding end of the opposite recess in each of said frame members, said spring support members each being located respectively within the spaces between said side portions of said flat sleeve members and extending laterally across the latter; and a plurality of spring members each of which is mounted in said spaces between the sides of said sleeve members and each bearing at one end thereof against said spring support members and at the other end thereof against an inner end of said sleeve members distant from and facing said spring support members.

5. An expandable link-strap comprising, in combination, a plurality of frame members lo cated adjacent to each other and each having a ilat body portion terminating in a pair of oppositely located trough like recesses, said recesses being substantially parallel to each other and confronting each other and sai-d ilat body-portion forming a continuation of one of the sides of said recesses so that said recesses are located in their entirety on one side of said flat body portion of said frame member;,a plurality of iiat sleeve members interconnecting adjacent pairs of said frame members which are located next to each other, said flat sleeve members each having a pair of opposite side portions located in spaced and parallel relation to each other and connected at their ends by a pair of end portions formed integrally with said side portions and extending beyond the edges of said side portions so as to form projections, said projections being located in said trough like recesses of said frame members and said side portions of said sleeve members being located between said recesses, said sleeve members each extending from a point intermediate the ends of one frame member beyond the latter to a point intermediate the ends of the next frame member; a plurality of elongated spring support members each having a central portion of a maximum width which is substantially less than 1/3 of the length thereof and having ends located in said recesses of said frame members at one end thereof, said ends being offset with respect to said central portion by a distance at least as great as the width of said central portion so that said spring support members each extend from the end of one recess to the corresponding end of the opposite recess in each of said frame members, said spring support members each being located respectively within the spaces between said side portions of said flat sleeve members and extending laterally across the latter; and a plurality of spring members each of which is mounted in said spaces between the sides of said sleeve members and each bearing at one end thereof against said spring support members and at the other end thereof against an inner end of said sleeve members distant from and facing said spring support members, said inner end of said sleeve members being formed with a recess to support said other end of said spring member.

6. An expandable link-strap comprising, in combination, a plurality of frame members located adjacent to each other and each having a fiat body portion terminating in a pair of oppositely located trough like recesses, said recesses being substantially parallel to each other and confronting each other and said flat body-portion forming a continuation of one of the sides of said recesses so that said recesses are located in their entirety on one side of said flat body portion of said frame member; a plurality of flat sleeve members interconnecting adjacent pairs of said frame members which are located next to each other, said flat sleeve members each having a pair of opposite side portions located in spaced and parallel relation to each other and connected at their ends by a pair of end portions formed integrally with said side portions and extending beyond the edges of said side portions so as to form projections, said projections being formed integrally with said side portions of said sleeve member and being located in said trough like recesses of said frame members and said side portions of said sleeve members being located between said recesses, said sleeve members each extending from a point intermediate the ends of :one frame member beyond the latter to a point intermediate the ends of the next frame member; a plurality of elongated spring support members each having a central portion of a maximum width which is substantially less than ,1/3 of the length thereof and having ends located in said recesses of said frame members at one end thereof, said ends being offset with respect to said central portion by a distance at least as great as the width of said central portion so that said spring support members each extend from the end of one recess to the corresponding end of the opposite recess in each of said frame members, said spring support members each being located respectively within the spaces between said side portions of said flat sleeve members and extending laterally across the latter; and a plurality of spring members each of which is mounted in said spaces between the sides of said sleeve members and each bearing at one end thereof against said spring support members and at the other end thereof against an inner end of said sleeve members located distant from and facing said spring members, said inner end of said sleeve members being formed with a recess to support said other end of said spring member.

7. A sleeve member for use in an expandable link strap, being formed of a single elongated strip of material curved transversely about substantially in a central region thereof so as to form a pair of sides spaced from each other and having free ends adjacent each other, one of said free ends being bent towards the other and engaging and overlying said other free end, one of said sides being provided adjacent the free end thereof with a pair of transversely extending oppositely located rst projections, the other of said. sides having adjacent the free end thereof a pair of transversely extending opp-ositely located second projections, one of said pairs of projections being of larger width than the other of said pairs of projections and being curled about and embracing said other of said pairs of projections whereby, the free ends of the sides are connected together by engagement of said first projections with said second projections.

8. A sleeve member for use in an expandable link strap, being formed of a single elongated strip of material curved transversely about substantially 180 in a central region thereof so as to form a pair of sides spaced from each other and having free ends adjacent each other, one of said sides having the free end thereof bent towards the free end of the other side and engaging and overlying the same, and one of said free ends being formed with a notched recess extending transversely thereof, said one side being provided adjacent the free end thereof with a pair of transversely extending oppositely located first projections, the other of said sides being provided adjacent the free end thereof with a pair of transversely extending oppositely located second projections, one of said pairs of projections being of larger width than the other of said pairs of projections and being curled about and embracing said other of said pairs of projections, whereby the free ends of the sides are connected together by engagement of said first projections with said second projections.

EMIL KIEFER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,670,663 Johnson May 22, 1928 1,672,007 Stelter June 5, 1928 1,692,809 Bigney Nov. 27, 1928 2,561,381 Kiefer July 24, 1951 FOREIGN PATENTS Number Country Date 178,761 England Apr. 27, 1922 

